PV=nRTScience: The equation in ideal gas laws that will allow you to find an unknown variable given the other three ("R" is a constant .08206) "P" is the pressure measured in ATM. "V" is the volume measured in liters. "n" is the number of moles dealt with in the problem. "T" is the absolute temperature.

Julie: I hate Chemistry. All of those problems are so hard. And what was that latest thing we learned... pervnrt? What the heck is that about?
Bob: PV=nRT... it's just catchy, idiot!